This invention relates to a recycling method for scrap silicon which can manufacture high-purity silicon from scrap silicon which contains impurity elements as dopants and which is produced during the manufacture of silicon products such as silicon wafers.
In order to increase the rate of utilization of silicon raw materials, it is desired to reutilize scrap which is produced during the manufacture of silicon wafers from silicon ingots (referred to below as “scrap silicon”). However, scrap silicon contains impurities, so it is necessary to increase its purity before it can be reused.
Japanese Published Unexamined Patent Application Hei 10-245216 discloses that the yield of silicon can be increased by recovering scrap silicon which is produced during the manufacture of silicon for solar cells and returning the recovered scrap silicon to a refining step.
However, that publication merely discloses a technique for increasing the yield of silicon in the manufacture of silicon for solar cells.